In designing lighting devices, e.g. by employing solid-state light radiation sources such as LED radiation sources, the need may arise to protect the device against the outer environment (e.g. in terms of Ingress Protection or IP).
Various implementations may envisage, as a protection element, a protection screen of a plastic material. This solution, however, may not be able to meet the flammability requirements imposed by some international standards, or the need to ensure good optical properties (essentially the transparency to light radiation) during the lifetime of the product.
In order to meet such requirements one may resort to glass covers (e.g. screens); besides being advantageously inexpensive, such covers may offer good protection features against electrical shocks and as regards flammability.
The use of glass covers also offers other advantages, e.g. the possibility of an easy removal of the glass protection cover in order to permit maintenance or replacement with a different cover having different optical properties (e.g. as regards diffusion, transparency, colour, scattering of the light radiation and so on).
The need may moreover be felt to make the mounting process of the lighting device quick and easy, without degrading other properties such as:                the possibility of achieving a good protection (e.g. IP-grade) level in a stable and reliable mounting structure (also as regards thermal stresses),        device ventilation, so as to offer stable and reliable luminous flux properties, and/or        the possibility of combining several lighting devices in arrays.        